Space Environmental Effects on Selected Long Duration Exposure Facility Polymeric Materials
1993; American Chemical Society; Linguagem: Inglês
10.1021/bk-1993-0527.ch018
ISSN1947-5918
AutoresPhilip R. Young, Wayne S. Slemp,
Tópico(s)Space Exploration and Technology
ResumoThe National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided a unique environmental exposure of a wide variety of materials. The effects of 5 years and 9 months of low-Earth orbit (LEO) exposure of these materials to atomic oxygen (AO), ultraviolet and particulate radiation, meteorid and debris, vacuum, contamination, and thermal cycling is providing a data base unparalleled in the history of space environment research. Working through the Environmental Effects on Materials Special Investigation Group (MSIG), a number of polymeric materials in various processed forms have been assembled from LDEF investigators for analysis at the NASA Langley Research Center. Specimens include silvered perfluorinated ethylene propylene (FEP) Teflon thermal blanket material, polysulfone and epoxy matrix resin/graphite fiber reinforced composites, and several high performance polymer films. These samples came from numerous spacecraft locations and, thus, received different environmental exposures. This paper reports the chemical characterization of these materials. The results of infrared, thermal, x-ray photoelectron, and various solution property analyses have shown no significant change at the molecular level in the polymer that survived exposure. However, scanning electron and scanning tunneling microscopies show resin loss and atexturing of the surface of some specimens which resulted in a change in optical properties. The potential effect of a silicon-containing molecular contamination on these materials is addressed. The possibility of continued post-exposure degradation of some polymeric films is also proposed.
Referência(s)